Wheel bracket mounting structure

ABSTRACT

A wheel bracket mounting structure which includes an elongated and flexible bracket member having an axle mounting section and a stem mounting section at generally opposite ends thereof. The axle mounting section includes a generally flat, platelike portion. The stem mounting section includes an elongate, generally arcuate stem adapted to be directly attached to a support member on a wheeled vehicle. An intermediate section is provided between the axle mounting section and the stem mounting section. A segment is provided at the juncture between the intermediate section and the flat, platelike portion to provide a region remote from the arcuate stem about which the platelike portion can elastically flex relative to the arcuate stem.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Ser. No. 875,523 filed June19, 1986, now abandoned which is a continuation of U.S. Ser. No. 541,599filed Oct. 13, 1983, now abandoned.

FIELD OF THE INVENTION

This invention relates to a wheel bracket mounting structure and amethod for making it, and more particularly to a wheel bracket mountingstructure having a single bracket part preferably made by a singlestamping step and from which the axle is cantilevered.

BACKGROUND OF THE INVENTION

Wheel bracket assemblies, which include a wheel bracket and a wheelrotatably supported on the bracket, are utilized in many applications,for example on shopping carts. In applications of this type, the wheelbracket assembly is frequently subjected to rough treatment andtherefore must be durable and reliable. However, in industries which arehighly competitive, it is also important that the wheel bracket assemblybe relatively inexpensive in order to minimize the overall cost of thefinal product.

One conventioral wheel bracket assembly used in applications of thistype includes U-shaped horn with the wheel rotatably supported betweenits legs, and a pin which is riveted in an opening in the bight of thehorn and has transverse holes drilled therethrough. Although thisconvenvional arrangement has been adequate for its intended purposes, ithas not been satisfactory in all respects. In particular, severalseparate manufacturing steps are required to fabricate the wheelbracket, thus making the wheel bracket assembly relatively expensive.Further, the connection between the pin and horn is subjected torelatively large stresses and frequently tends to loosen over a periodof time.

A further consideration is that it is usually desirable for a wheelbracket assembly of the foregoing type to have a small amount ofpivoting and shock-absorbing capability when mounted on a shopping cartor other device, in order to minimize the stresses applied to thebearings. However, conventional arrangements which provide limitedpivoting and/or shock-absorbing capability typically involve increasedstructural complexity of the wheel bracket assembly and thus anincreased number of manufacturing steps to fabricate the wheel bracketassembly.

Accordingly, an object of the present invention is to provide a wheellracket mounting structure which is simple in structure and isrelatively simple and inexpensive to manufacture.

A further object of the invention is to provide a wheel bracket mountingstructure, as aforesaid, which can be fabricated with a minimum numberof steps and with a minimal amount of labor.

A further object of the invention is to provide a wheel bracket mountingstructure, as aforesaid, which is rugged and durable and requires littleor no maintenance over its useful lifetime.

A further object of the invention is to provide a wheel bracket mountingstructure, as aforesaid, which has an aesthetically pleasing appearanceand preferably a somewhat streamlined shape.

A further object of the invention is to provide a wheel bracket mountingstructure, as aforesaid, which has a shock-absorbing capability whenmounted on a shopping cart or similar wheeled vehicle.

A further object of the invention is to provide a wheel bracket mountingstructure, as aforesaid, wherein the bracket structure is renderedelastically movable relative to the structure on which it is mounted tofurther enhance the shock-absorbing capability of the wheel bracketmounting structure.

A further object of the invention is to provide a wheel bracket mountingstructure, as aforesaid, wherein the axle is secured to the bracketmember at only one end thereof.

SUMMARY OF THE INVENTION

The objects and purposes of the broadest aspect of the invention,including those set forth above, are met by providing a wheel bracketmounting structure which includes an elongated and flexible bracketmember having an axle mounting section and a stem mounting section atgenerally opposite ends thereof. The axle mounting section includes afirst structure defining a generally flat, platelike portion. The stemmounting section includes second structure defining an elongate,generally arcuate stem adapted to be directly attached to a supportmember on a wheeled vehicle. The bracket member further includes thirdstructure intermediate the aforesaid first and second structure forproviding a smooth transition between the first and second structures.The third structure includes a segment adjacent the platelike portionfor providing a region remote from the arcuate stem about which theplatelike portion can elastically flex relative to the arcuate stem. Theobjects and purposes are also met by providing a method of making thebracket member, as aforesaid.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the invention will be described in more detailhereinafter in connection with the exemplary embodimemts illustrated inthe drawings, in which:

FIG. 1 is a side view of a wheel supported vehicle, namely, a shoppingcart having a wheel bracket mounting structure embodying the inventionmounted thereon;

FIG. 2 is an enlarged front view of a wheel bracket mounting structureembodying the invention and taken along the, line II--II of FIG. 1;

FIG. 2A is a fragmentary sectional view taken along the line IIA--1IA inFIG. 2;

FIG. 3 is a sectional view taken along the line III--III of FIG. 2.

FIG. 4 is a sectional view taken along the line IV--IV of FIG. 2;

FIG. 5 is a front elevational view of a second embodiment of the wheelbracket mounting structure;

FIG. 6 is a sectional view taken along the line VI--VI of FIG. 5;

FIG. 7 is a front elevational view of a third embodiment of the wheelbracket mounting structure embodying the invention;

FIG. 8 is a sectional view taken along the line VIII--VIII of FIG. 7;

FIG. 9 is a front elevational view of a fourth embodiment of the wheelbracket mounting structure embodying the invention;

FIG. 10 is a sectional view taken along the line X--X of FIG. 9;

FIG. 11 is a front elevational view of a fifth embodiment of the wheelbracket mounting structure embodying the invention;

FIG. 12 is a sectional view taken along the line XII--XII of FIG. 11;

FIG. 13 is a front elevational view of a sixth embodiment of the wheelbracket mounting structure embodying the invention;

FIG. 14 is a sectional view taken along the line XIV-XIV of FIG. 13;

FIG. 15 is a front elevational view of a seventh embodiment of the wheelbracket mounting structure embodying the invention;

FIG. 16 is a sectional view taken along the line XVI--XVI of FIG. 15;

FIG. 17 is a sectional view taken along the line XVI--XVI of FIG. 15;

FIG. 18 is a front elevational view of an eighth embodiment of the wheelbracket mounting structure embodying the invention;

FIG. 19 is a sectional view taken along the line XIX--XIX of FIG. 18;and

FIG. 20 is a sectional view taken along the line XX--XX of FIG. 18.

Certain terminology is used in the following description for conveniencein reference only and is not to be considered limiting. For example, thewords "up", "down", "front" and "rear" will designate directions in thedrawings to which reference is made. The words "in" and "out" willrespectively refer to directions toward and away from the geometriccenter of the wheel bracket mounting structure and designated partsthereof. Such terminology will include the words specifically mentionedabove, derivatives thereof and words of similar import.

DETAILED DESCRIPTION

A conventional type of wheeled vehicle 10 is illustrated in FIG. 1. Thewheeled vehicle is comprised of a base frame 11 having the usual pivotalor castored front wheels 12 and fixed or stationary rear wheels 13. Inthis particular embodiment, the rear wheels 13 include a wheel bracketmounting structure which embodies the invention and, accordingly, thefollowing discussion will be directed to the various embodiments of therear wheel bracket mounting structure. Of particular importance is thedownwardly extending and opening tubular segment 14 of the base frame11, since it is to this segment that the wheel bracket mountingstructure is secured.

Referring to FIG. 2, the lower portion of the tubular segment 14 isillustrated therein. As stated above, the tubular segment 14 is the partof the base frame 11 to which the wheel bracket mounting structure issecured. More specifically, the wheel bracket mounting structureincludes an elongated and flexible bracket member 16 having at oppositeends thereof an axle supporting section 17 and a stem section 18. In allembodiments described hereinafter, the bracket member 16 is formed froma single piece of metal of uniform thickness, preferably a high carbonsteel plate such as type C-1065 and, after the stamping operation, ispreferably heat treated and drawn to give it a Rockwell hardness ir therange of 45 to 55 Rockwell C and preferably 48 to 52 Rockwell C. Thisessentially converts the bracket member to spring steel. Thethus-increased tensile strength of the steel will enable the steel towithstand substantial shock loads without any plastic deformation.

In the embodiment of FIGS. 2 to 4, the stem section 18 is formed into asplit cylinder 19. The diameter of the cylinder 19 is equal to orinitially slightly greater than the internal diameter of the tubularsegment 14 in the base 11 of the wheeled vehicle 10. If the cylinder 19is initially larger in diameter than the internal diameter of thetubular segment 14, there will normally be a space provided between themutually adjacent edges thereof, as at 15, to enable the assembler orinstaller to pinch the edges together so that the effective diameterbecomes less than the internal diameter of the tubular segment tofacilitate an insertion of the cylinder 19 into the tubular segment 14.Thereafter, the edges will separate due to the resilience of the steelto snugly hold the cylinder in the tubular segment. The cylinder 19 hasa sufficient length to be received a substantial distance inside thetubular segment 14 as illustrated in FIG. 2. In this particularembodiment, a pair of vertically spaced and aligned holes 21 areprovided in both the tubular segment 14 and the cylinder 19, eachreceiving a rivet 22 therein to securely hold the cylinder 19 to thetubular segment 14 and to prevent relative rotation therebetween.

An intermediate section 23 is provided on the bracket member between theaxle mounting section 17 and the stem section 18. The intermediatesection flares smoothly downwardly and laterally outwardly from thelower end of the stem section 18, is bulbously curved in a manner suchthat the centerpoints of all radii of curvature lie on the side of saidbracket member adjacent said wheel, and increase in width in a directionaway from the stem segment 18. There are no sharp corners in theintermediate section. That is, the intermediate section 23 has a roundedcontour to prevent elastic flexing occurring at the juncture between theintermediate section 23 and the stem section 18 as well as along thelength of the intermediate section. It is desirable for there to be arigid relationship between the stem section 18 and the intermediatesection 23. The intermediate section then becomes less wide, preferablyuniformly tapers toward the axle mounting section 17.

The axle mounting section 17 is contiguous with the lower portion of theintermediate section 23 and is horizontally and vertically offset fromthe stem section 18. The axle mounting section 17 is generally a flat,platelike portion extending in a plane parallel to the central axis 37of the cylinder 19. The juncture between the axle mounting section 17and the intermediate section 23, namaly at 24, defines a region whereatelastic flexing is desirable. The intermediate section 23 has,therefore, a greater resistance to lateral elastic flex than the regionindicated by the reference character 24. The purpose of this particularstructure will be explained below.

The axle mounting section has a noncircular opening 26 punchedtherethrough (see FIG. 2A). A solid axle member 27 is provided and has anecked down-portion 28 received in the noncircular opening 26 as shownin FIG. 2A. The axis 29 of the axle 27 is oriented preferablyperpendicular to the plane of the flat, platelike, axle mounting section17. The material of the necked down-portiion 28 is deformed into a rivethead 31. Simultaneously during this forming of the rivet head 31, themetal is caused to flow and fill the voids 32 (FIG. 2A) of thenoncircular opening 26 to fixedly and rigidly lock the axle 27 to theaxle mounting section 17. An enlargement 30 is provided on the axis 27at the free end thereof to prevent or stop the wheel 13 from movingaxially away from the bracket member 16.

As shown in FIG. 4, the axis 29 is offset horizontally and to the rearof the central axis 37 of the cylinder 19.

In this particular embodiment, the axle 27 is identical to the ax;edisclosed in my U.S. Pat. No. 4,318,204. In fact. the entirety of thewheel 13 including the axle therefor is identical to the wheel disclosedin my aforementioned patent. Accordingly, reference thereto is to beincorporated herein. It is, of course, to be understood that other wheelconstructions can also be utilized in combination with the bracketmember described hereinabove without departing from the scope of theinvention. In other words, the disclosure is not to be consideredlimited to the particular wheel shown in FIG. 2. Thus, a detaileddiscussion of the particular characteristics of the wheel is deemedunnecessary.

In addition to the relative flexing movement that is permitted betweenthe plane of rotation of the wheel 13 relative to the axis 29 permittedby the thick and elastic segments 33 and 34 of the liner 36, and asdescribed in my aforementioned U.S. Pat. No. 4,318,204, a flexing of theaxle mounting section 17 relative to the intermediate section 23 ispermitted to facilitate a flexing movement of the axis 29 to a secondaryposition illustrated by the reference 29A. This particular feature of mybracket member becomes important for the following reasons. In use ofthe wheel bracket mounting structure which includes the aforementionedbracket member 16 and axle 27 mounted thereon combined with theparticular features of the axle mounting section 17 and stem section 18,both of which are isolated by an intermediate section 23, severe loadsare applied to the wheel, particularly in an axial direction as opposedto the normal loads applied in the radial direction. These axial loadsare generally caused by the user of a wheeled vehicle, such as ashopping cart, pushing on the vehicle handle in a direction which causesa load to be applied to the tread of the wheel as indicated by the arrowF in FIG. 2. While the aforementioned thick and elastic segments 33 and34 of the liner 36 have been heretofore sufficient to compensate forthis type of load, it has been discovered that in certain situationsadditional loads have been applied to the wheel bracket assemblies usedheretofore and have resulted in a plastic deformation of the bracketmember. My invention, however, is to provide structure which will enablefurther compensation of these additional loads applied to the overallwheel bracket mounting structure. In my arrangement, I provide for anelastic flexing to occur at the region 24 between the intermediatesection 23 and the axle mounting section 17 of the bracket member 16enabling the axis 29 to shift temporarily under severe load to thealternate position illustrated by the reference character 29A. Thisflexing will be in addition to the flexing that I normally provide whenwheels are used which are capable of such flexing movement, particularlythose wheels disclosed in my U.S. Pat. No. 4,318,204 Re. U.S. Pat. No.31,110. Both of the wheel stuctures disclosed in these patents havesolid axles. However, it is to be recognized that axle structures suchas is disclosed in my U.S. Pat. No. 4,072,373 are capable of use withthis invention, it being recognized that the axle must be fixedlysecured to the axle mounting section 17.

During testing of the wheel bracket mounting structure describedhereinabove, certain surprising results were achieved. For example, andreferring to the structure disclosed and claimed in my copendingapplication Ser. No. 488,863, filed Apr. 26, 1983, a series of loadswere applied to the tread of the wheel at a location corresponding tothe location indicated by the reference arrow F in FIG. 2 herein. Theamount of flex was then measured (distance B) to indicate the amount ofelastic flexing that was permitted between the normal plane of rotationP1 and a secondary plane of rotation P2 caused by the application of theforce so indicated. The following chart indicates the results as appliedto the structure disclosed in my aforementioned application Ser. No.488,863, particularly FIG. 2 therein, and utilizing a 5 inch diameterwheel.

    ______________________________________                                        F (pounds)  B (deflection in inches)                                          ______________________________________                                        10          .065                                                              20          .122                                                              30          .205                                                              40          .284                                                              50          .385                                                              60          .467                                                              70          .570                                                              80          .653                                                              90          .748                                                              100         .853                                                              ______________________________________                                    

The structure of FIGS. 2 to 4 were subjected to the same test, using thesame wheel, and the following results were achieved, also utilizing a 5inch diameter wheel:

    ______________________________________                                        F (pounds)  B (deflection in inches)                                          ______________________________________                                        10          .168                                                              20          .298                                                              30          .415                                                              40          .555                                                              50          .705                                                              60          .845                                                              70          1.050                                                             80          1.230                                                             90          1.395                                                             100         1.580                                                             110         1.775                                                             ______________________________________                                    

The unexpected increase in the amount of deflection permitted by thestructure of FIGS. 2 to 4 has enhanced the durability of the bracketmember 16 and enables same to be subjected to severe loads withoutplastically deforming the bracket member. When the bracket member 16 isemployed on wheels used on shopping carts, clerks returning shoppingcarts to the interior of the store, by first gathering plural carts in anested relationship in the parking lot and pushing them, one nestedwithin the other, oftentimes encounter locations whereat the entirenested arrangement of shopping carts must be turned at a right angle. Itis at this point in time that a severe load is applied to the wheel atthe location indicated by the reference arrow F in FIG. 2. It is also atthis point in time that a severe load is applied to the wheel bracketmounting structure. The provision of the bracket member which I havedescribed above in reference to FIGS. 2 to 4 enables the wheel bracketmounting structure to withstand the severe load and, following atermination of the severe load, return to its normal position enablingthe wheel 13 to return to its proper plane of rotation P1.

In reference to this testing, the metal employed for the bracket member16 was 11-gauge (0.120 inches thick) and the internal diameter of thetubular segment 14 was 0.720 inches in diameter. The metal used in thetesting of the arrangement disclosed in my aforementioned applicationSer. No. 488,863 employed a metal having a 12-gauge thickness (0.104inches thick) and the internal diameter of the tubular segment was, aswith the embodiment disclosed in FIGS. 2 to 4 of this application, 0.720inches in diameter.

ALTERNATE EMBODIMENT OF FIGS. 5-6

The embodiment of FIGS. 5 and 6 is similar to the embodiment of FIGS. 2to 4 described above. Therefore, the same reference numerals will beused to designate similar or identical structure described above inrelation to FIGS. 2 to 4 but with a "1" prefix added thereto. That is,the bracket member 116 is composed of an axle mounting section 117 and astem section 118 separated by an intermediate section 123. As with theembodiment of FIGS. 2 to 4, the intermediate section 123 has a greaterresistance to elastic flex than does the juncture 124 between theintermediate section 123 and the axle mounting section 117. In thisparticular embodiment, the stem section 118 is not cylindrical in shapebut is, instead, semicylindrical in shape as shown at 38 in FIG. 6. Toform a cylinder, the same as the cylinder 19 in the embodiment of FIGS.2 to 4, an additional skirt member 39 is formed having a stem section 41thereon which is semicylindrical in shape, which when placed in matingrelationship with the semicylindrical portion 38 of the stem section 118forms a cylinder 119. The cylinder 119 is received in the tubularsegment 14 and is secured in place by plural rivets 22 received inaligned openings 21 in the tubular segment 14 and the cylinder 119. Inthis particular embodiment, the skirt 39 has a lower segment 42 thatconforms to the shape of the upper part of the intermediate section 123so as to match the upper extremity of the intermediate part 123 toprovide continuity in the aesthetic appearance. It is to be noted thatthe skirt terminates at a location above the axle.

ALTERNATE EMBODIMENT OF FIGS. 7-8

The embodiment of FIGS. 7 and 8 is generally the same as the embodimentof FIGS. 5 and 6 and, as a result, the same reference numerals have beenutilized as were utilized in the description of FIGS. 5 and 6 which, insome instances, may have the suffix "A" added thereto to indicate theslight modification. The lower portion 42 of the skirt member 39 hasbeen eliminated in this embodiment leaving only the semicylindricalsection 41A which, when mated with the semicylindrical portion 38 of thebracket member 116 forms a cylinder 119.

The wheel bracket mounting structure of FIGS. 7 and 8 were subjected tothe same testing discussed above, and using a 5 inch diameter wheel,with the following results:

    ______________________________________                                        F (pounds)  B (deflections in inches)                                         ______________________________________                                        10           .225                                                             20           .535                                                             30           .775                                                             40          1.060                                                             50          1.380                                                             60          1.690                                                             70          1.965                                                             75          2.215                                                             ______________________________________                                    

It was observed that the primary difference between the amount offlexing for the embodiment of FIGS. 7 and 8 and the embodiment of FIGS.2 to 4 was due to a thinner gauge material being utilized for thisembodiment. That is, the embodiment of FIGS. 2 to 4 utilized an 11-gaugematerial (0.120 inches thick) as compared to a 12-gauge materia beingutilized in this embodiment (0.104 inches thick). This particularconstruction seemed to withstand the severe loading up to at least 75pounds without any permanent plastic deformation of the metal.

ALTERNATE EMBODIMENT OF FIGS. 9-10

The embodiment of FIGS. 9-10 is closely similar to the embodiment ofFIGS. 7 and 8 described above and, as a result, the same referencenumerals have been utilized to designate the identical components. Thatis, the bracket member 116 is identical to the bracket member 116 inthis particular embodiment. The primary difference between thisembodiment and the embodiment of FIGS. 7 and 8 is the provision of anelastomeric member 43 which is shaped to fill the interior of theC-shaped contour of the semicylindrical portion 38 of the stem section118 as well as fill out the remainder of the interior of the tubularsegment 14. Thus, the outer extremity of both the semicylindricalsegment 38 and the elastomeric member 43 is cylindrical to therebydefine the cylinder 119. Appropriate openings are provided through theelastomeric member 43 to facilitate the rivets 22 securing the bracketmember 16 and cooperating elastomeric member 43 to the interior of thetubular segment 14.

The elastomeric member in this embodiment, as in all other embodimentsdescribed herein, is made of a polyurethane having a hardness value inthe range of 75 Shore A to 55 Shore D Durometer.

ALTERNATE EMBODIMENT OF FIGS. 11-12

The embodiment of FIGS. 11 and 12 is similar to the embodiment of FIGS.9 and 10. Therefore, the same reference numeral will be used todesignate similar or identical structure described above in relation toFIGS. 2 to 4 but with a "2" prefix added thereto. There is a slightvariation, however, in the specific shape of the bracket member 216,particularly the shape of the intermediate segment 223 wherein a roundedcorner at 44 is provided whereas in the embodiment of FIGS. 9 and 10 arather sharp corner is provided. In addition, the stem section 218 isshaped slightly differently from the embodiment of FIGS. 9 and 10. Inthis particular embodiment, the stem segment 218 is somewhat C-shapedhaving a pair of parallel legs 46 and 47 which extend in parallel planeswhich are both parallel to an upright vertical plane extending throughthe axis 29. The legs 46 and 47 are connected by a bight section havingan exterior surface that is arcuate and corresponds to the arcuatecontour of the interior of the tubular segment 14. Further, a space 49is provided between the exterior of the leg 46 and the interior of thetubular segment 14 as well as a space 51 between the exterior of the leg47 and the interior of the tubular segment 14 as best illustrated inFIG. 12. An elastomeric member 52 is provided and is adapted to fill thespace between the parallel legs 46 and 47 as well as the spaces 49 and51 and, further, the remainder portion of the interior of the tubularsegment 14 to define a cylinder 119. The exterior surface of thecylinder 119 is composed of two parts, namely, the exterior surface ofthe bight 48 as well as the exterior surface of the elastomeric member52 as best illustrated in FIG. 12.

The elastomeric member in this embodiment, as in all other embodimentsdescribed herein, is made of a polyurethane having a hardness value inthe range of 75 Shore A to 55 Shore D Durometer.

In this particular embodiment, the bight section 48 is provided with asingle hole therethrough which is aligned with the single set of alignedholes 21 provided in the tubular segment 14 so that a single rivet 22effects a securing of the stem section 218 to the tubular segment 14. Inthis particular embodiment, the hole through the bight 48 is slightlylarger than the diameter of the central portion of the rivet so that theentirety of the bracket member 216 will move relative to the tubularsegment 14 against the resilient urging of the elastomeric member 52. Itis to be noted that each of the legs 46 and 47 each have an edge 53thereon which is inclined to the vertical as best illustrated in FIG.11. The edge effectively constitutes a removal of material from the legs46 and 47 to facilitate further relative movement between the bracketmember 216 and the tubular segment 14. That is, the bracket member 216is movable, for example, to the broken line position illustrated in FIG.11 about an axis oriented perpendicular to the axis of the rivet 22against the resilient urging of the elastomeric member 52.

The wheel bracket mounting structure of FIGS. 11 and 12 was subjected tothe same type of testing as was the previously discussed embodiments ofFIGS. 2 to 4 and FIGS. 7 and 8. The following are the test resultsderived from the test. A 5 inch diameter wheel was used in this testing.

    ______________________________________                                        F (pounds)  B (deflection in inches)                                          ______________________________________                                        10           .360                                                             20           .695                                                             30           .965                                                             40          1.325                                                             50          1.610                                                             60          2.050                                                             70          2.388                                                             80          2.800                                                             85          3.000                                                             100         4.500                                                             ______________________________________                                    

Additional force was applied to the wheel until a maximum deflection of5 inches was achieved and without any plastic deformation of thebracket.

The material of the bracket member 216 was 11-gauge steel. The spacingbetween the exterior surfaces of the parallel legs 46 and 47 was 0.500inches and the distance from the midportion of the exterior surface ofthe bight 48 to the axially facing edges of the legs 46 and 47 adjacentthe juncture between the stem section 218 and the intermediate section223 was 0.425 inches. The interior diameter of the tubular segment wasthe same as the previous embodiments, namely, 0.720 inches.

ALTERNATE EMBODIMENT OF FIGS. 13-14

The embodiment of FIGS. 13 and 14 is similar in many respects to theembodiment of FIGS. 2 to 4 and, as a result, the same reference numeralswill be used to designate similar or identical structure described inrelation to FIGS. 2 to 4 but with a "3" prefix added thereto. Thebracket member 316 has a cylindrically shaped stem section 318 separatedfrom the axle mounting segment 317 by an intermediate segment 323. Thecylinder 319 of the stem section 318 has a diameter that is less thanthe interior diameter of the tubular segment 14 thereby defining a space54 therebetween. An elastomeric sleeve is provided and fills the space54 between the exterior surface of the cylinder 319 and the interiorsurface of the tubular segment 14. In this particular embodiment, thesleeve 56 has a cylindrical body part and a closed end section 57. Fordecorative purposes, a radially outwardly extending annular lip 58 isprovided and grips over and covers the lower annular edge 59 of thetubular segment 14. A pair of vertically spaced and parallel openingsare provided in the cylinder 319 as well as in the wall of the tubularsegment 14 and the cylindrical shell portion of the elastomeric sleeve56 so as to facilitate the reception therein of rivets 22 to effect asecurement of the stem section 318 to the tubular segment 14.

The elastomeric member in this embodiment, as in all other embodimentsdescribed herein, is made of a polyurethane having a hardness value inthe range of 75 Shore A to 55 Shore D Durometer.

As with the embodiments of FIGS. 2 to 4, FIGS. 7 and 8 and FIGS. 11 and12, this embodiment was also subjected to a test wherein a force wasapplied to the tread of the wheel 13 in direction of the arrow Fillustrated in FIG. 13. The amount of deflection B was measured and thefollowing are the results obtained from such testing.

    ______________________________________                                        F (pounds)  B (deflection in inches)                                          ______________________________________                                        10          .130                                                              20          .260                                                              30          .370                                                              40          .440                                                              50          .560                                                              60          .720                                                              70          .850                                                              80          1.030                                                             90          1.150                                                             100         1.380                                                             140         2.500                                                             ______________________________________                                    

The internal diameter of the tubular segment 14 in this particularembodiment was 0.830 inches. The interior diameter of the cylindricalsleeve portion of the elastomeric sleeve 56 was 0.720 inches and theouter diameter thereof was 0.830 inches. The material of the bracketmember 316 was 11-gauge steel. Further, and with all testing discussedherein, the wheel 13 was 5 inches in diameter.

ALTERNATE EMBODIMENT OF FIGS. 15-17

The embodiment of FIGS. 15 to 17 is similar in many respects to theembodiment of FIGS. 2 to 4 and, as a result, the same reference numeralswill be used to designate similar or identical structure described inrelation to FIGS. 2 to 4 but with a "4" prefix added thereto. That is,the bracket member 416 has a cylindrical stem section 418 and a flat,platelike, axle mounting section 417 separated by a bulbously contouredintermediate section 423. The primary differences between thisembodiment and the embodiment of FIGS. 2 to 4 is the orientation of theflat, platelike, axle mounting section 417 in a plane which is inclinedto the vertical. In this particular embodiment, the plane of the flat,platelike, axle mounting section 417 is, as with the previouslydiscussed embodiments, parallel to the plane of rotation of the wheel13A. The axis 29 of the axle for the wheel extends perpendicular to theplane of the axle mounting section 417. The plane of rotation P1 for thewheel 13A is inclined to the vertical by an angle β equal to 3° to 5°.The tread of the wheel 13A is configured so that the entire width of thetread 61 engages the ground even though the plane of rotation P1 thereofis inclined to the vertical by the aforementioned angle β. In all otherrespects, the wheel 13A is identical to the wheel 13 disclosed in theembodiment relating to FIGS. 2 to 4.

Another feature that is different in this embodiment is that the bracketmember 416 is located on the outside of the wheel when it is mounted ona wheeled vehicle, such as the wheeled vehicle 10 illustrated in FIG. 1.In the previously discussed embodiments, the bracket member 16 was, ineach instance, mounted on the inside of the wheel. I have provided abracket member 416 capable of supporting the wheel on the inside thereofso that the exterior of the wheel supported vehicle will appear the sameas conventional rear brackets except that the bracket member 416 iscomprised of a single piece of steel. In this particular embodiment, theaxis 37 of the cylinder 419 defined by the stem section 418 is containedin a plane which extends parallel to the longitudinal axis of thewheeled vehicle 10 and is oriented in an obtuse angle α relative to theplane of rotation P1 for the wheel 13A. In this particular embodiment,the angle α is in the range of 175° to 177°, namely, the complement tothe angle β. The purpose behind inclining the plane of rotation P1 forthe wheel 13A to the vertical is to provide additional space between themutually adjacent portions of the tread 61 and the surface of thebracket member 16. Since relative movement capability exists between thewheel 13A and the bracket member 16 due to the particular bearingsupport in the wheel 13A, sufficient space has to be provided to enablethe wheel to move relative to the bracket member 416 without causing thetread 61 to scrub against the inside surface portion of the intermediatesection 423 when the wheel is flexed to the broken line position shownin FIG. 15.

ALTERNATE EMBODIMENT OF FIGS. 18-20

In certain instances, it may be desirable to support the axle rotatablysupporting a wheel from both ends thereof. Further, a particularcustomer may demand this type of support for the wheel even though thepreviously discussed embodiments will adequately tolerate most abusesrendered to a wheel bracket mounting structure. However, as explainedabove and with respect to the structure disclosed in my copendingapplication Ser. No. 488,863, insufficient flex was possible between thewheel bracket mounting structure and the tubular segment before plasticdeformation occurred in the structure of the bracket members. Irecognized in my earlier filed application Ser. No. 488,863 that anelastomeric sleeve could be placed around the stem section to enhancethe relative movement characteristic between the bracket members and thetubular segment. In this particular instance, the following test resultsoccurred when a force was applied to the tread of a wheel shown in FIG.12 in my aforementioned copending application to cause a flexing of theplane of rotation P1 to an alternate position P2 thereof. A 5 inchdiameter wheel was used on this testing.

    ______________________________________                                        F (pounds)  B (deflection in inches)                                          ______________________________________                                        10           .305                                                             20           .462                                                             30           .594                                                             40           .700                                                             50           .810                                                             60           .913                                                             70          1.015                                                             80          1.090                                                             90          1.180                                                             100         1.280                                                             110         1.380                                                             120         1.468                                                             ______________________________________                                    

In this test, the material of the bracket members was 11-gauge steel andthe diameter of the stem section was 0.720 inches and the exteriordiameter of the elastomeric sleeve was 0.830 inches, namely, the same asthe internal diameter of the tubular segment 14. This particularconstruction has been satisfactory for most uses discovered to date.However, there are certain applications wherein larger forces must beabsorbed in order to prevent plastic deformation of the bracket members.FIGS. 18 to 20 represent my improvement over the earlier structuresdisclosed in the aforementioned application Ser. No. 488,863.

Referring now more specifically to the structure of FIGS. 18 to 20, thewheel bracket mounting structure consists of a pair of bracket members62 and 63 which are the mirror image of each other. The bracket member62 has a flat, platelike, axle mounting section 64 and asemicylindrically shaped stem section 66 separated from the axlemounting section by a bulbously contoured intermediate section 67. Thebracket 63 also has a flat, platelike, axle mounting section 68 as wellas a semicylindrically shaped stem section 69 separated from the axlemounting section by a bulbously contoured intermediate section 71. Inthis particular embodiment, the stem section 69 has a section thereofadjacent the upper edge which is removed to form an inclined edge 72. Inaddition, a single opening 73 is provided in the stem sections 66 and69, the axis of which extends in an upright vertical plane parallel tothe longitudinal axis of a wheeled vehicle on which the wheel bracketmounting structure is secured. In this particular embodiment, the planeis identified by the reference character P3 in FIG. 18.

As with the previously discussed embodiments, the intermediate sections67 and 71 of both bracket members 62 and 63, respectively, have agreater resistance to lateral flex than the junctures 74 and 76,respectively, between the aforesaid intermediate sections 67 and 71 andthe associated axle mounting sections 64 and 68. However, an axle issecured to and extends between the axle mounting sections to eliminatethe elastic flex at the junctures 74 and 76.

The wheel 13B oriented between the bracket members 62 and 63 can be ofany construction including wheels having a hollow axle as opposed to asolid axle. One such wheel employing a hollow axle is disclosed in myU.S. Pat. No. 4,072,373.

An opening 77, smaller in diameter than the opening 73, is provided indiametrically opposite sides of the tubular segment 14A of the baseframe of a wheeled vehicle, the axis of which also extends parallel tothe plane P3. In the embodiments of FIGS. 2 to 17 discussed above, theaxis of the rivets all extended perpendicular to the plane P1, namely, aplane corresponding to the aforementioned plane P3. Prior to insertionof the stem sections 66 and 69 into the interior of the tubular segment14A, the lower end of the tubular segment 14A is enlarged as bestillustrated in FIG. 19. That is, the lower end of the tubular segment14A has a generally elliptical shape wherein the left and right halvesof the opening have a radius R with the centerpoints of each radii beingspaced apart approximately the diameter of the central portion of therivet 78 as best illustrated in FIG. 19. During assembly of the bracketmembers 62 and 63 to the tubular segment 14, the opening 73 is alignedwith the opening 77 and a rivet 78 is inserted therein. The enlargedopposite ends on the rivet 78 are best illustrated in FIG. 20. Anelastomeric sleeve 79 is provided and encircles the stem sections 66 and69. In this particular embodiment, the plane of rotation P1 of the wheel13B is oriented at an angle β relative to an upright vertical planeextending parallel to the longitudinal axis of a wheeled vehicle onwhich such wheel is mounted. In this particular embodiment, the angle βis oriented in the range of 3° to 5° from the vertical as illustrated inFIG. 18. The elastomeric sleeve 79 occupies the space between theperipheral surface of the stem sections 66 and 69 and the internalsurface of the tubular segment 14A. Since the stem sections 66 and 69forming a cylinder are inclined to the vertical, the elastomeric sleeve79 has a special shape to fill the space between the exteriorcylindrical surface formed by the stem sections 66 and 69 and theinterior of the enlarged lower segment of the tubular segment 14A. Asillustrated in FIG. 19, the elastomeric sleeve 79 will have a uniformthickness around the stem section 69 but a varying and enlargedthickness around the stem section 66.

The elastomeric member in this embodiment, as in all other embodimentsdescribed herein, is made of a polyurethane having a hardness value inthe range of 75 Shore A to 55 Shore D Durometer.

The embodiment of FIGS. 18 to 20 was subjected to a test wherein a forcewas applied to the tread in the direction of the arrow F illustrated inFIG. 18. The deflection of the plane of rotation from the position P1 toalternate positions illustrated by the plane P2 was measured. Inaddition, the amount of lateral movement C of the bracket members 62 and63, particularly, the axle mounting sections 64 and 68, were noted. Thefollowing test results were obtained. A 5 inch diameter wheel was usedin this testing.

    ______________________________________                                        F (pounds) B (deflection in inches)                                                                      C (in inches)                                      ______________________________________                                        10          .100           .070                                               15          .200           .150                                               20          .320           .230                                               25          .465           --                                                 30          .675           --                                                 35          .860           .275                                               40          .970           .355                                               45         1.078           .460                                               50         1.198           .520                                               55         1.275           .575                                               60         1.355           .630                                               65         1.430           .685                                               70         1.475           .717                                               75         1.532           .757                                               80         1.621           .830                                               85         1.695           .860                                               90         1.760           .880                                               95         1.830           .940                                               100        1.970           --                                                 110        2.045           --                                                 120        2.155           --                                                 130        2.340           --                                                 140        2.500           --                                                 ______________________________________                                    

The material of the bracket members 62 and 63 comprised 12-gauge steeland the wheel 13B was 5 inches in diameter. Further, the specific angleof the plane P1 relative to the vertical plane P3 at the start of thetest was 3°. Further, the upper section of the tubular segment 14A hadan interior diameter of 0.830 inches. The lower internal dimension ofthe tubular segment 14A, from left to right in FIG. 19, was 1.03 inches.In other words, there was a 0.100 inch flare on each side of the tubularsegment from the central axis of the tubular segment 14A. Thus, theamount of lateral flex achieved by the embodiment of FIGS. 18 to 20 wasmore than twice that amount obtained by the FIG. 2 structure and morethan 50 percent that amount obtained by the FIG. 12 structure disclosedin my aforementioned earlier filed application Ser. No. 488,863 and asevidenced by the data presented hereinabove.

Although particular preferred embodiments of the invention have beendisclosed in detail for illustrative purposes, it will be recognizedthat variations or modifications of the disclosed apparatus, includingthe rearrangement of parts, lie within the scope of the presentinvention.

The embodimennts of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A wheel bracket mountingstructure, comprising:a unitary elongated bracket member including asingle axle mounting section to secure only one end of an axle memberand a stem mounting section at generally opposite ends thereof, saidaxle mounting section including first means defining a generally flat,platelike portion vertically and horizontally offset from said stemmounting section, said axle member being rigidly secured and cantileverdto said flat, platelike portion, the axis of said axle member extendinggenerally perpendicularly to the plane of said flat, platelike portion,said stem mounting section including second means defining an elongatestem means generally arcuate in cross-section adapted to be directlyattached to a support member on a wheeled vehicle, said bracket memberfurther including a first bulbously shaped structure means intermediatesaid first and second means for providing a smooth transitiontherebetween for resisting lateral elastic flexing so that said stemmounting section and said first bulbously shaped structure means areresistant to relative lateral elastic flexing, said stem mountingsection and said first bulbously shaped structure means consisting of amajority of the length of said bracket member, and third means defininga region at the juncture between said flat, platelike portion and saidfirst bulbously shaped structure means for allowing the material of saidbracket in said region at said juncture to elastically flex relative tosaid first bulbously shaped structure means and said stem mountingsection, said first bulbously shaped structure means and said stemmounting section having a greater resistance to lateral elastic flexcharacteristic than said region.
 2. The wheel bracket mounting structureaccording to claim 1, including a wheel and bearing means rotatablysupporting said wheel on said axle member; andwherein stop means areprovided on said axle member for preventing axial movement of said wheelin a direction away from said flat, platelike portion, whereby said axleis movable with said flat, platelike portion during said elasticallyflex movement thereof.
 3. The wheel bracket mounting structure accordingto claim 1, wherein said bracket member is made of a single piece ofuniformly thick, high carbon steel, heat treated and drawn to a Rockwellhardness in the range of 45 to 55 Rockwell C.
 4. The wheel bracketmounting structure according to claim 1, wherein when said stem means isconnected to a wheeled vehicle, said platelike portion being oriented ina vertical plane parallel to the longitudinal axis of said stem means.5. The wheel bracket mounting structure according to claim 1, whereinwhen said stem means is connected to a wheeled vehicle, said platelikeportion being oriented in a plane which is inclined to the vertical andout of parallel relationship to the longitudinal axis of said stemmeans.
 6. The wheel bracket mounting structure according to claim 1,whereinsaid first shaped structure means resists elastic flex in adirection radial to said axle segment.
 7. The wheel bracket mountingstructure according to claim 1, wherein when said stem means isconnected to a wheeled vehicle, said platelike portion being oriented ina vertical plane parallel to the longitudinal axis of said stem means;andwherein said axle member extends from a side of said platelikeportion thereby orienting a central plane of said wheel rotatablymounted thereon in alignment with the longitudinal axis of said stemmeans.
 8. The wheel bracket mounting structure according to claim 1,wherein when said stem means is connected to a wheeled vehicle, saidplatelike portion being oriented in a vertical plane parallel to thelongitudinal axis of said stem means;wherein said axial member extendsfrom a side of said platelike portion thereby orienting a central planeof said wheel rotatably mounted thereon at an obtuse angle greater than170° but less than 180° to a vertially aligned plane containing saidlongitudinal axis of said stem means and oriented parallel to therolling direction of said wheel about said axis of said axle member. 9.The wheel bracket mounting structure according to claim 8, wherein saidobtuse angle is in the range of 175° to 177°.
 10. The wheel bracketmounting structure according to claim 1, wherein said stem meansincludes the material of said bracket member bent into a closed,cylindrical form.
 11. The wheel bracket mounting structure according toclaim 8, wherein said stem means includes an elastomeric sleeveencircling said closed, cylindrical form.
 12. The wheel bracket mountingstructure according to claim 1, wherein said stem means includes thematerial of said bracket member bent into a first semicylindricalsegment and a separate and second semicylindrical segment juxtaposedsaid first semicylindrical segment to thereby define a cylinder.
 13. Thewheel bracket mounting structure according to claim 10, wherein saidsecond semicylindrical segment includes means defining a skirtintegrally secured thereto and having a shape mirror imaging at least aportion of said third means adjacent said stem mounting section.
 14. Thewheel bracket mounting structure according to claim 1, wherein said stemmeans includes the material of said bracket member bent into asemicylindrical segment and an elastomeric member having a first portionfilling the space between the legs of said semicylindrical segment and asecond portion integral with said first portion having a shapeconforming to the shape of said semicylindrical segment to thereby forma cylinder.
 15. The wheel bracket mounting structure according to claim1, wherein said stem means includes the material of said bracket memberbent into a C shape, the legs of which lie in spaced and parallelplanes, and an elastomeric member having a first portion filling thespace between said legs of said C-shaped member and a second portionintegral with said first portion having a shape conforming to the shapeof a portion of said C-shaped member to at least define a cylinder. 16.The wheel bracket mounting structure according to claim 13, wherein theupper region of the vertically extending edges of said legs are inclinedto the vertical toward a bight portion of said C-shaped member extendingbetween said parallel legs.
 17. A wheel bracket mounting structure,comprisinga unitary elongated bracket member including an axle mountingsection and a stem mounting section at generally opposite ends thereof,said axle mounting section including first means defining a generallyflat, platelike portion vertically and horizontally offset from saidstem mounting section, said stem mounting section including second meansdefining an elongate stem means generally arcuate in cross-sectionadapted to be directly attached to a support member on a wheeledvehicle, said bracket member further including a first bulbously shapedstructure means intermediate said first and second means for providing asmooth transition therebetween for resisting lateral elastic flexing sothat said stem mounting section and said first bulbously shapedstructure means are resistant to relative lateral elastic flexing, saidstem mounting section and said first bulbously shaped structure meansconsisting of a majority of the length of said bracket member, and thirdmeans defining a region at the juncture between said flat, platelikeportion and said first bulbously shaped structure means for allowing thematerial of said bracket in said region at said juncture to elasticallyflex relative to said first bulbously shaped structure means and saidstem mounting section, said first bulbously shaped structure means andsaid stem mounting section having a greater resistance to lateralelastic flex characteristic than said region.
 18. A wheel bracketmounting structure according to claim 17, including an axle memberrigidly secured and cantilevered to said flat, platelike portion, theaxis of said axle member extending generally perpendicularly to theplane of said flat, platelike portion.
 19. The wheel bracket mountingstructure according to claim 17, including a further elongated bracketmember that is a mirror image to the first mentioned bracket member,said bracket members each having a semicylindrical stem mounting sectionand a bulbously contoured first shaped structure means providing saidsmooth transition between said stem mounting section and said axlemounting section, said bracket members being oriented side-by-side sothat said semicylindrical stem mounting sections define a cylinder andsaid axle mounting sections are horizontally spaced from each other, anaxle fixedly connected to and extending between said axle mountingsections and a wheel rotatably supported on said axle.
 20. The wheelbracket mounting structure according claim 17, wherein said axle and itsconnection to said axle supporting sections eliminates the elastic flexat said juncture.
 21. The wheel bracket mounting structure according toclaim 20, wherein an elastomeric member encircles said cylinder and isreceived in a downwardly opening and vertically oriented tubular segmenton a wheeled vehicle, and wherein pivot means are provided for pivotallysecuring said bracket members to said tubular segment, said elastomericmember yieldably resisting pivotal movement of said bracket members. 22.The wheel bracket mounting structure according to claim 21, wherein saidpivot means includes an axis which extends parallel to a plane ofrotation of said wheel.
 23. The wheel bracket mounting structureaccording to claim 21, wherein the lower end portion of said tubularsegment is flared outwardly in directions lateral to a plane of rotationof said wheel; andwherein said plane of rotation of said wheel and theaxis of said cylinder are oriented at an acute angle to the vertical;and wherein said elastomeric member is formed to occupy the spacebetween said cylinder and the internal wall of said flared part of saidtubular segment.